How to use 2.8's default HDRi's in renders?
The default HDR images can be found in your installation folder:

[Windows] - C:\Program Files\Blender Foundation\Blender &lt;version&gt;\&lt;version&gt;\Datafiles\Studiolights\World\
[MacOS] - /Applications/Blender/Contents/Resources/&lt;version&gt;/Datafiles/Studiolights/World/
[Linux] - /opt/Blender &lt;version&gt;/&lt;version&gt;/Datafiles/Studiolights/World/

In the World section, set the surface type to Background and the Color to use Environment Texture. Then select the HDR image you would like to use: